Methods and systems for starting a gas turbine engine

ABSTRACT

Methods and systems of starting a gas turbine engine are provided. During startup, a fuel pressure associated with a primary fuel supply of the gas turbine engine is monitored. A low-pressure event for the primary fuel supply is detected when the fuel pressure falls below a predetermined threshold. Responsive to detecting the low pressure event, an electric backup boost pump is activated by an engine controller to provide fuel to the gas turbine engine.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.16/552,200 filed on Aug. 27, 2019, the entire contents of which arehereby incorporated by reference.

TECHNICAL FIELD

The present disclosure relates generally to gas turbine engines, andspecifically to starting gas turbine engines.

BACKGROUND OF THE ART

In a gas turbine engine, continuous inlet air is compressed, mixed withfuel in an inflammable proportion, and exposed to an ignition source toignite the mixture which then continues to burn to produce combustionproducts. The engine ignition process involves certain challenges, whichcan result in ignition failure for gas turbine engine.

As such, there is room for improvement.

SUMMARY

In accordance with at least one broad aspect, there is provided a methodof starting a gas turbine engine. During startup, a fuel pressureassociated with a primary fuel supply of the gas turbine engine ismonitored. A low-pressure event for the primary fuel supply is detectedwhen the fuel pressure falls below a predetermined threshold. Responsiveto detecting the low pressure event, an electric backup boost pump isactivated by an engine controller to provide fuel to the gas turbineengine.

In according with at least one other broad aspect, there is provided asystem for starting a gas turbine engine. The system comprises aprocessing unit and a non-transitory computer-readable memorycommunicatively coupled to the processing unit. The computer-readablememory comprises comprising computer-readable program instructionsexecutable by the processing unit for: monitoring, during startup, afuel pressure associated with a primary fuel supply of the gas turbineengine; detecting a low-pressure event for the primary fuel supply whenthe fuel pressure falls below a predetermined threshold; and responsiveto detecting the low pressure event, activating, by an enginecontroller, an electric backup boost pump to provide fuel to the gasturbine engine.

In accordance with at least one further broad aspect, there is provideda system for starting a gas turbine engine. The system comprises apressure sensor producing fuel pressure readings associated with aprimary fuel supply of the gas turbine engine. The system furthercomprises an engine controller coupled to the pressure sensor for:monitoring, during startup, the fuel pressure readings; detecting alow-pressure event for the primary fuel supply when at least one of thefuel pressure readings falls below a predetermined threshold; andresponsive to detecting the low pressure event, activating an electricbackup boost pump to provide fuel to the gas turbine engine.

Features of the systems, devices, and methods described herein may beused in various combinations, in accordance with the embodimentsdescribed herein.

DESCRIPTION OF THE DRAWINGS

Reference is now made to the accompanying figures in which:

FIG. 1 is a cross-sectional view of an example turboshaft engine of anaircraft;

FIG. 2 is a block diagram of an example system for starting an engine;

FIG. 3 is a flowchart of an example method for starting a gas turbineengine; and

FIG. 4 is a block diagram of an example computing device forimplementing the method of FIG. 3 .

It will be noted that throughout the appended drawings, like featuresare identified by like reference numerals.

DETAILED DESCRIPTION

With reference to FIG. 1 , a gas turbine engine 100 is shown. In thisexample, the engine 100 is a turboshaft engine. It should be noted,however, that the techniques described herein are considered to beapplicable to other types of gas turbine engines, including turbofan,turboprop, and turbojet engines, and to other types of combustionengines, including Wankel engines and reciprocating engines.

The engine 100 generally comprises in serial flow communication a lowpressure (LP) compressor section 12 and a high pressure (HP) compressorsection 14 for pressurizing air, a combustor 16 in which the compressedair is mixed with fuel and ignited for generating an annular stream ofhot combustion gases, a high pressure turbine section 18 for extractingenergy from the combustion gases and driving the high pressurecompressor section 14, and a lower pressure turbine section 20 forfurther extracting energy from the combustion gases and driving at leastthe low pressure compressor section 12.

The low pressure compressor section 12 may independently rotate from thehigh pressure compressor section 14. The low pressure compressor section12 may include one or more compression stages and the high pressurecompressor section 14 may include one or more compression stages. Acompressor stage may include a compressor rotor, or a combination of thecompressor rotor and a compressor stator assembly. In a multistagecompressor configuration, the compressor stator assemblies may directthe air from one compressor rotor to the next.

The engine 100 has multiple, i.e. two or more, spools which may performthe compression to pressurize the air received through an air inlet 22,and which extract energy from the combustion gases before they exit viaan exhaust outlet 24. In the illustrated embodiment, the engine 100includes a low pressure spool 26 and a high pressure spool 28 mountedfor rotation about an engine axis 30. The low pressure and high pressurespools 26, 28 are independently rotatable relative to each other aboutthe axis 30. The term “spool” is herein intended to broadly refer todrivingly connected turbine and compressor rotors.

The low pressure spool 26 includes a low pressure shaft 32interconnecting the low pressure turbine section 20 with the lowpressure compressor section 12 to drive rotors of the low pressurecompressor section 12. In other words, the low pressure compressorsection 12 may include at least one low pressure compressor rotordirectly drivingly engaged to the low pressure shaft 32 and the lowpressure turbine section 20 may include at least one low pressureturbine rotor directly drivingly engaged to the low pressure shaft 32 soas to rotate the low pressure compressor section 12 at a same speed asthe low pressure turbine section 20. The high pressure spool 28 includesa high pressure shaft 34 interconnecting the high pressure turbinesection 18 with the high pressure compressor section 14 to drive rotorsof the high pressure compressor section 14. In other words, the highpressure compressor section 14 may include at least one high pressurecompressor rotor directly drivingly engaged to the high pressure shaft34 and the high pressure turbine section 18 may include at least onehigh pressure turbine rotor directly drivingly engaged to the highpressure shaft 34 so as to rotate the high pressure compressor section14 at a same speed as the high pressure turbine section 18. In someembodiments, the high pressure shaft 34 may be hollow and the lowpressure shaft 32 extends therethrough. The two shafts 32, 34 are freeto rotate independently from one another.

The engine 100 may include a transmission 38 driven by the low pressureshaft 32 and driving a rotatable output shaft 40. The transmission 38may vary a ratio between rotational speeds of the low pressure shaft 32and the output shaft 40.

With reference to FIG. 2 , there is shown a system 200 for starting agas turbine engine, for instance the engine 100. The system 200 iscomposed of an engine controller 210, a fuel system 220, optionally apressure sensor 230, and optionally an electrical relay 240. The enginecontroller 210 can control various aspects of the operation of theengine 100, including, but not limited to, modulating a rate of fuelflow provided to the engine 100, adjusting the position and/ororientation of variable geometry mechanisms within the engine 100,adjusting a bleed air level of the engine 100, and the like. In someembodiments, the engine controller 210 is configured for controllingoperation of multiple engines.

For example, the engine controller 210 can be provided as one or moreFull Authority Digital Engine Controllers (FADECs) or similar devices.The engine controller 210 is configured for receiving variousinstructions from an operator of the engine 100 and/or of an aircraft orother vehicle of which the engine 100 is a component. In addition, theengine controller 210 can provide to the operator various informationabout the operation of the engine 100. In some embodiments, the enginecontroller 210 controls the operation of the engine 100 via one or moreelectrical and electronic communication pathways. Alternatively, or inaddition, the engine controller 210 controls the operation of the engine100 via one or more actuators, mechanical linkages, hydraulic systems,and the like.

The fuel system 220 is composed of a reservoir 222 which serves tocontain fuel to supply the engine 100 via a fuel conduit 228. Fuel inthe reservoir 222 can be conveyed to the engine 100 via the fuel conduit228, for example by operation of a primary fuel supply 224 and/or abackup boost pump 226. The primary fuel supply 224 can include anysuitable type of fuel pump or other mechanism for conveying fuel fromthe reservoir 222 to the engine 100. The backup boost pump 226 can beany suitable type of fuel pump or other mechanism which is also forconveying fuel from the reservoir 222 to the engine 100, and whichoperates independently from the primary fuel supply 224. For example,the primary fuel supply 224 can be a suction- or pressure-based pump,and the backup boost pump 226 can be an electrical pump. In thisfashion, the backup boost pump 226 can, in some embodiments, provide aseparate failure mode for supplying fuel to the engine 100. The fuelconduit 228 can be any suitable type of pipe, channel, or the like,which facilitates the flow of fuel to the engine 100.

The primary fuel supply 224 can be controlled by way of an avionicssystem associated with an aircraft of which the engine 100 is acomponent, or by way of any other suitable control system independentfrom the engine controller 210. The backup boost pump 226 can also becontrolled by the avionics system or other control system independentfrom the engine controller 210. In some embodiments, the fuel system 220includes a plurality of backup boost pumps 226, or includes additionalbackup fuel delivery systems which serve to convey fuel from thereservoir 222 to the engine 100, whether via the fuel conduit 228 or viaanother fuel conduit.

The optional pressure sensor 230 serves to measure a fuel pressureassociated with the engine 100, that is to say, a fuel pressure for fuelsupplied to the engine 100 from the fuel system 220. The pressure sensor230 can be a pressure transducer, a pressure switch, or any othersuitable device for measuring pressure of a fluid. The pressure sensor230 can report the fuel pressure to the engine controller 210. Althoughshown here as being coupled to the fuel conduit 228, it should beunderstood that the pressure sensor 230 can be coupled to a fuel inletof the engine 100, to a fuel outlet of the primary fuel supply 224, to afuel outlet of the fuel system 220 generally, to any other suitablecomponent of the fuel system 220, or to any other suitable componentwhich allows the pressure sensor 230 to measure the fuel pressureassociated with the engine 100. In some embodiments, the functionalityof the pressure sensor 230 is embedded in, or otherwise combined with,the engine controller 210, and the pressure sensor 230 can be omitted.For example, the engine controller 210 can make use of a virtual sensor,that is to say, a software-based sensor which produces a reading basedon data from other sensors, to derive the fuel pressure.

The fuel system 220 provides the engine 100 with fuel to cause ignitionof the engine 100, to maintain the engine 100 in an operating state, andthe like. In many operating states, the engine 100 is provided with fuelfrom the fuel system 220 principally via the primary fuel supply 224,with the backup boost pump 226 being used in the event of failure of theprimary fuel supply 224.

The engine controller 210 can monitor the fuel pressure to determinewhether the fuel system 200 is providing the engine 100 with sufficientfuel pressure. In some embodiments, the engine controller 210 monitorsthe fuel pressure by receiving fuel pressure readings, for instance fromthe pressure sensor 230. The fuel pressure readings can be receivedsubstantially in real-time, can be encoded or represented in anysuitable fashion, and can be obtained by the engine controller 210 viaany suitable wired and/or wireless communication channels. In someembodiments, the engine controller 210 monitors the fuel pressure forthe engine 100 during startup of the engine 100. This can includemonitoring the fuel pressure for the engine 100 during any phase of anignition sequence of the engine 100, and/or during any phase of areignition sequence of the engine 100. In other embodiments, the enginecontroller 210 monitors the fuel pressure for the engine 100 duringcertain phases of flight of an aircraft of which the engine 100 is acomponent, for instance during takeoff, landing, and/or other relayphases. In some further embodiments, the engine controller 210 monitorsthe fuel pressure for the engine 100 in response to the occurrence ofparticular event, for instance following a flameout event or the like.

By monitoring the fuel pressure associated with the engine 100, theengine controller 210 can detect the occurrence of low-pressure eventsfor the fuel system 200. A low-pressure event occurs when the fuelpressure associated with the engine 100 falls below a predeterminedthreshold. In the case of the primary fuel supply 224, it can be saidthat the primary fuel supply 224 experiences a low-pressure event whenthe fuel pressure associated with the engine 100 falls below thepredetermined threshold while the primary fuel supply 224 is responsiblefor providing the engine 100 with fuel from the reservoir 222.

In some embodiments, a low-pressure event is detected when one or morefuel pressure readings fall below the predetermined threshold. In someother embodiments, a low-pressure event is detected when multipleconsecutive fuel pressure readings fall below the predeterminedthreshold, or when a predetermined number of fuel pressure readings fallbelow the predetermined threshold within a predetermined time period. Insome further embodiments, a low-pressure event is detected when arolling average of the fuel pressure readings, for instance as assessedover a predetermined interval of time, falls below the predeterminedthreshold. In some still further embodiments, a low-pressure event isdetected based on a trend (i.e. first derivative) of the fuel pressurereadings, for instance before any individual one of the pressurereadings falls below the predetermined threshold.

Other approaches are also considered. For example, the system 200 caninclude a plurality of pressure sensors 230, and the engine controller210 can evaluate fuel pressure readings from the plurality of pressuresensors 230 to confirm whether a low-pressure event has occurred. Thepredetermined threshold against which the fuel pressure is compared canbe any suitable value. In some embodiments, the predetermined thresholdand/or the criteria for detecting a low-pressure event is established bya standards agency or regulatory authority.

In response to detecting a low-pressure event for the primary fuelsupply 224, the engine controller 210 can activate the backup boost pump226 in order to provide fuel to the engine 100. In some embodiments, theengine controller 210 is substantially directly connected to the backupboost pump 226, and issues a command to the backup boost pump 226 tocause activation thereof. In other embodiments, the engine controller210 is connected to the backup boost pump 226 via the electrical relay240, and commands activation of the backup boost pump 226 via theelectrical relay 240.

The electrical relay 240 can be any suitable type of relay device forcausing activation of the backup boost pump 226. In some embodiments,the electrical relay 240 is mounted to a vehicle of which the engine 100is a component. For instance, if the engine 100 is part of an aircraft,the electrical relay 240 can be mounted to an airframe of the aircraft.In other cases, the electrical relay 240 can be mounted to anothercomponent of the vehicle. The engine controller 210 can be connected tothe electrical relay 240 in any suitable fashion, and the backup boostpump 226 can be coupled to the electrical relay in any suitable fashion.

In operation, the engine controller 210 can monitor the fuel pressureassociated with the engine 100 and, responsive to detecting a lowpressure event while the primary fuel supply 224 is supplying fuel tothe engine 100, activate the backup boost pump 226. In this fashion, theengine controller 210 can attempt to rectify fuel-flow related issuesindependently from any avionics systems or other control systems, forinstance to ensure continued operation of the engine 100.

In some embodiments, the engine controller 210 begins to monitor thefuel pressure, for instance via the pressure sensor 230, in response todetecting an engine flameout event for the engine 100. An engineflameout refers to unintended shutdown of an engine due to theextinction of flames in the combustion chamber, which in some cases iscaused by low fuel pressure to the engine 100. For example, the enginecontroller 210 can detect a flameout event for the engine 100, and canthen arm the backup boost pump 226 in response to detecting the flameoutevent. For instance, the backup boost pump 226 can be armed prior todetecting the low pressure event, which can ensure that the backup boostpump 226 is capable of providing fuel to the engine 100 within a shorttime period once the low pressure event is detected.

In some embodiments, the engine controller 210 activates the backupboost pump 226, in response to the low pressure event, for apredetermined time delay. Following the time delay, the enginecontroller 210 can deactivate the backup boost pump 226, for instance toassess whether the primary fuel supply 224 is functional and can supplysufficient fuel pressure to the engine 100. If a subsequent low pressureevent is detected, the engine controller 210 can reactivate the backupboost pump 226.

The engine controller 210 can be configured for periodically cycling thebackup boost pump 226 off and on to assess whether the primary fuelsupply 224 is functional. For example, the engine controller 210 cankeep the backup boost pump 226 active for a few seconds or a fewminutes, then deactivate the backup boost pump 226 to assess whether theprimary fuel supply 224 is functional, then reactivate the backup boostpump 226 if the primary fuel supply is non-functional. In someembodiments, this cycle can continue indefinitely, or until an operatorof the engine 100, or of an aircraft or other vehicle of which theengine 100 is a component, instructs the engine controller 210 to haltthe cycling of the backup boost pump 226. For instance, the enginecontroller 210 can receive, via an operator input, a command to halt thecycling of the backup boost pump.

In some embodiments, the fuel system 220 additionally includes one ormore fuel filters, which can be located within the fuel conduit 228, atfuel outlets for the primary fuel supply 224 and/or the backup boostpump 226, between the reservoir 222 and the primary fuel supply 224and/or the backup boost pump 226, or at any other suitable location.Alternatively, or in addition, the engine 100 can include a fuel filter,for instance at a fuel inlet thereof. It can occur that fuel filtersbecome congested; that is say, that the ability of the fuel filter toproperly convey fuel becomes diminished. Fuel filters become congestedover time, due to accumulation of particulate matter in the fuel whichpasses through the fuel filters.

In certain embodiments, the system 200 can additionally be used todetermine whether fuel filters of the fuel system 220 and/or of theengine 100 have become congested. The fuel pressure readings obtained bythe engine controller 210, for instance from the pressure sensor 230,can be acquired and stored, for instance within the engine controller210 or within a separate data repository. Based on multiple acquiredfuel pressure readings, the engine controller 210 can assess whetherfuel filters have become congested. In response to detecting that a fuelfilter is congested, the engine controller 210 can produce an alertassociated with the fuel filter, for instance to inform an operator ofthe engine 100 that a maintenance action should be performed on the fuelfilter. This can include cleaning the filter and/or replacing thefilter, as appropriate.

For example, a gradual decline in fuel pressure from the primary fuelsupply, for instance over a predetermined period of time, can beindicative of a fuel filter in the fuel conduit 228 having becomecongested. In another example, a number of consecutive fuel pressurereadings which are below the predetermined threshold for a low-pressureevent can be indicative of a fuel filter in the fuel conduit 228 havingbecome congested.

In some cases, different pressure sensors 230 can be positioned onopposing sides of a fuel filter. For instance, for a fuel filter locatedwithin the fuel conduit 228, a first pressure sensor 230 can be locatedbetween the primary fuel supply 224 and the fuel filter, and a secondpressure sensor 230 can be located between the fuel filter and theengine 100. If a decrease or drop in fuel pressure, for instance above apredetermined threshold, is detected across the fuel filter, this canindicate that the fuel filter has become congested.

In cases where the backup boost pump 226 and the primary fuel supply 224use different fuel conduits 228 to provide fuel to the engine 100, theengine controller 210 can command activation of the backup boost pump226 in response to detecting that a fuel filter in the fuel conduit 228for the primary fuel supply 224 has become clogged. This may assist inreducing the risk of lack of fuel to the engine 100, and/or the risk offuel pump cavitation for the primary fuel supply 224.

With reference to FIG. 3 , there is illustrated a method 300 forstarting a gas turbine engine, for instance the engine 100. At step 302,a fuel pressure associated with a primary fuel supply of the engine 100,for instance the primary fuel supply 224, is monitored during startup.In some embodiments, the fuel pressure is monitored by way of a pressuresensor, for instance the pressure sensor 230. In some embodiments, thefuel pressure is monitored responsive to detecting a flameout event forthe engine 100.

Optionally, at step 304, a backup boost pump associated with the engine100 is armed, for instance the backup boost pump 226 of the fuel system220. The backup boost pump 226 can be armed in response to detecting theflameout event for the engine 100, or concurrently with beginning tomonitor the fuel pressure at step 302.

At decision step 306, a determination is made regarding whether a lowpressure event for the primary fuel supply 224 has been detected. A lowpressure event can be detected when the fuel pressure associated withthe primary fuel supply 224 falls below a predetermined threshold. Whena low pressure event has been detected, the method 300 moves to step308. When no low pressure event has been detected, the method 300 movesto some previous step, for instance step 302.

At step 308, when a low pressure event has been detected, the backupboost pump 226 of the fuel system 220 is activated by an enginecontroller, for instance the engine controller 210, to provide fuel tothe engine 100. In some embodiments, the backup boost pump 226 isactivated via an electrical relay, for instance the electrical relay240, which provides electrical power to the backup boost pump 226 andwhich is activated by the engine controller 210.

Optionally, at step 310, it can be determined whether a fuel filter ofthe primary fuel supply 224 is congested based on a plurality ofacquired pressure readings, for instance from the pressure sensor 230.For example, the engine controller 210 can detect a gradual decrease infuel pressure across the fuel filter, which can indicate that the fuelfilter is congested. In some embodiments, the engine controller 210 canproduce an alert associated with the fuel filter, for instance to informan operator of the engine 100 that a maintenance action should beperformed on the fuel filter.

Optionally, at step 312, the backup boost pump 226 can be deactivated,for instance after a predetermined time delay. After the backup boostpump 226 has been deactivated, the method 300 can return to someprevious step, for instance the step 302, and resume monitoring the fuelpressure associated with the primary fuel supply 224. In this fashion,an assessment can be made regarding whether the primary fuel supply 224is functional. If the primary fuel supply 224 is non-functional, asubsequent low pressure event will be detected at step 306, and thebackup boost pump 226 can be reactivated at step 308. The method 300 cancontinue looping indefinitely, as appropriate, or can be halted, forinstance in response to receipt of an operator input.

With reference to FIG. 4 , the method 300 may be implemented by acomputing device 410, which can embody part or all of the enginecontroller 210. The computing device 410 comprises a processing unit 412and a memory 414 which has stored therein computer-executableinstructions 416. The processing unit 412 may comprise any suitabledevices configured to implement the functionality of the processing unit230 and/or the functionality described in the method 300, such thatinstructions 416, when executed by the computing device 410 or otherprogrammable apparatus, may cause the functions/acts/steps performed bythe processing unit 230 and/or described in the method 300 as providedherein to be executed. The processing unit 412 may comprise, forexample, any type of general-purpose microprocessor or microcontroller,a digital signal processing (DSP) processor, a central processing unit(CPU), an integrated circuit, a field programmable gate array (FPGA), areconfigurable processor, other suitably programmed or programmablelogic circuits, custom-designed analog and/or digital circuits, or anycombination thereof.

The memory 414 may comprise any suitable known or other machine-readablestorage medium. The memory 414 may comprise non-transitory computerreadable storage medium, for example, but not limited to, an electronic,magnetic, optical, electromagnetic, infrared, or semiconductor system,apparatus, or device, or any suitable combination of the foregoing. Thememory 414 may include a suitable combination of any type of computermemory that is located either internally or externally to device, forexample random-access memory (RAM), read-only memory (ROM), compact discread-only memory (CDROM), electro-optical memory, magneto-opticalmemory, erasable programmable read-only memory (EPROM), andelectrically-erasable programmable read-only memory (EEPROM),Ferroelectric RAM (FRAM) or the like. Memory 414 may comprise anystorage means (e.g., devices) suitable for retrievably storingmachine-readable instructions 416 executable by processing unit 412.

It should be noted that the computing device 410 may be implemented aspart of a FADEC or other similar device, including electronic enginecontrol (EEC), engine control unit (EUC), engine electronic controlsystem (EECS), and the like. In addition, it should be noted that thetechniques described herein can be performed by the engine controller210 substantially in real-time, during operation of the engine 100, forexample during a flight mission.

The methods and systems for starting a gas turbine engine as describedherein may be implemented in a high level procedural or object orientedprogramming or scripting language, or a combination thereof, tocommunicate with or assist in the operation of a computer system, forexample the computing device 410. Alternatively, the methods and systemsdescribed herein may be implemented in assembly or machine language. Thelanguage may be a compiled or interpreted language.

Embodiments of the methods and systems described herein may also beconsidered to be implemented by way of a non-transitorycomputer-readable storage medium having a computer program storedthereon. The computer program may comprise computer-readableinstructions which cause a computer, or more specifically the processingunit 412 of the computing device 410, to operate in a specific andpredefined manner to perform the functions described herein, for examplethose described in the method 300.

Computer-executable instructions may be in many forms, including programmodules, executed by one or more computers or other devices. Generally,program modules include routines, programs, objects, components, datastructures, etc., that perform particular tasks or implement particularabstract data types. Typically the functionality of the program modulesmay be combined or distributed as desired in various embodiments.

The above description is meant to be exemplary only, and one skilled inthe art will recognize that changes may be made to the embodimentsdescribed without departing from the scope of the present disclosure.Still other modifications which fall within the scope of the presentdisclosure will be apparent to those skilled in the art, in light of areview of this disclosure.

Various aspects of the systems and methods described herein may be usedalone, in combination, or in a variety of arrangements not specificallydiscussed in the embodiments described in the foregoing and is thereforenot limited in its application to the details and arrangement ofcomponents set forth in the foregoing description or illustrated in thedrawings. For example, aspects described in one embodiment may becombined in any manner with aspects described in other embodiments.Although particular embodiments have been shown and described, it willbe apparent to those skilled in the art that changes and modificationsmay be made without departing from this invention in its broaderaspects. The scope of the following claims should not be limited by theembodiments set forth in the examples, but should be given the broadestreasonable interpretation consistent with the description as a whole.

The invention claimed is:
 1. A method of starting a gas turbine engine,comprising: monitoring, during startup of the gas turbine engine, a fuelpressure associated with a primary fuel supply of the gas turbineengine, the primary fuel supply being configured to provide fuel from areservoir to the gas turbine engine; detecting a low-pressure event forthe primary fuel supply when the fuel pressure falls below apredetermined threshold, detecting the low pressure event including:comparing a plurality of pressure readings to the predeterminedthreshold; and detecting the low pressure event when at least two of theplurality of pressure readings are below the predetermined threshold;and responsive to detecting the low pressure event, activating, by anengine controller, an electric backup boost pump to provide fuel fromthe reservoir to the gas turbine engine, the electric backup boost pumpoperating independently of the primary fuel supply and drawing fuel fromthe reservoir separately of the primary fuel supply, wherein theplurality of pressure readings are detected along a common fuel conduit.2. The method of claim 1, wherein monitoring the fuel pressure isperformed responsive to detecting a flameout event for the gas turbineengine.
 3. The method of claim 2, further comprising arming the electricbackup boost pump responsive to detecting the flameout event and priorto detecting the low pressure event.
 4. The method of claim 1, furthercomprising: deactivating the electric backup boost pump after apredetermined time delay; detecting one or more subsequent low pressureevents for the primary fuel supply; and responsive to detecting the oneor more subsequent low pressure events, reactivating, by the enginecontroller, the electric backup boost pump to provide fuel to the gasturbine engine.
 5. The method of claim 1, further comprising: obtaininga request to halt the electric backup boost pump via an operator input;and halting, by the engine controller, the electric backup boost pump.6. The method of claim 1, further comprising: acquiring the plurality ofpressure readings over a time interval; and determining, based on theplurality of pressure readings, whether a fuel filter of the primaryfuel supply is congested.
 7. The method of claim 6, wherein determiningwhether the fuel filter is congested comprises detecting, within theplurality of pressure readings, a gradual decline in the fuel pressure.8. The method of claim 1, wherein activating the electric backup boostpump comprises activating, by the engine controller, an airframe-mountedrelay to provide electrical power to the electric backup boost pump. 9.A system for starting a gas turbine engine, comprising: a processingunit; and a non-transitory computer-readable memory communicativelycoupled to the processing unit and comprising computer-readable programinstructions executable by the processing unit for: monitoring, duringstartup of the gas turbine engine, a fuel pressure associated with aprimary fuel supply of the gas turbine engine, the primary fuel supplybeing configured to provide fuel from a reservoir to the gas turbineengine; detecting a low-pressure event for the primary fuel supply whenthe fuel pressure falls below a predetermined threshold, detecting thelow pressure event including: comparing a plurality of pressure readingsto the predetermined threshold; and detecting the low pressure eventwhen at least two of the plurality of pressure readings are below thepredetermined threshold; and responsive to detecting the low pressureevent, activating, by an engine controller, an electric backup boostpump to provide fuel from the reservoir to the gas turbine engine, theelectric backup boost pump operating independently of the primary fuelsupply and drawing fuel from the reservoir separately of the primaryfuel supply, wherein the plurality of pressure readings are detectedalong a common fuel conduit.
 10. The system of claim 9, whereinmonitoring the fuel pressure is performed responsive to detecting aflameout event for the gas turbine engine.
 11. The system of claim 9,wherein the computer-readable program instructions are executable by theprocessing unit for: deactivating the electric backup boost pump after apredetermined time delay; detecting one or more subsequent low pressureevents for the primary fuel supply; and responsive to detecting the oneor more subsequent low pressure events, reactivating, by the enginecontroller, the electric backup boost pump to provide fuel to the gasturbine engine.
 12. The system of claim 9, wherein the computer-readableprogram instructions are executable by the processing unit for:obtaining a request to halt the electric backup boost pump via anoperator input; and halting, by the engine controller the electricbackup boost pump.
 13. The system of claim 9, wherein thecomputer-readable program instructions are executable by the processingunit for: acquiring the plurality of pressure readings over a timeinterval; and determining, based on the plurality of pressure readings,whether a fuel filter of the primary fuel supply is congested.
 14. Thesystem of claim 9, wherein activating the electric backup boost pumpcomprises activating, by the engine controller, an airframe-mountedrelay to provide electrical power to the electric backup boost pump.